1. Field of the Invention
This invention pertains to a memory device, comprising a plate of magnetic material which is suitable for the storage of digital information in the form of magnetic domains and on which a domain guide structure is provided. The guide structure comprises discrete elements on which preferred positions for the domains can be formed at predetermined times under the control of drive means. The drive means drives the domains along the domain guide structure by the periodic formation of the preferred positions. The device also includes detection means for the selective and separate detection of domains in accordance with their information content.
2. Description of the Prior Art
Memory devices of this kind have been described in copending U.S. Pat. No. 4,091,459, herein incorporated by reference. In the known device the domains are driven by a rotary magnetic field along a domain guide structure which is mainly composed of T-elements and I-elements. It has been found that it is very difficult to realize a high drive frequency by means of such a rotary magnetic field; this is due to the inductance of the magnetic coils used.
The present invention has for its object to provide a domain memory which has a higher operating frequency at least as "seen" by the user. The invention further has for its object to enable a higher operating frequency for the input sections or output sections of the domain guide structure. The input and output of the information is thus quickly effected. A further characteristic aspect of the known device is the fact that all domains are driven under the control of the rotary magnetic field, so that complex organizations are required for isolating input/output paths from loop-shaped path sections which serve only for the storage of information. In this respect the invention also has for its object to provide a device with independent driving of the magnetic domains in different path sections. The invention aims to maintain the attractive properties of the known device as much as possible, notably the low dissipation per bit.